At first I was like what is this control scheme... but then oh, right lol, nevermind. Makes sense. Still, I won't complain about it, but it made the game a bit harder since the default controls ghost on my keyboard.
I think the difficulty is alright for the kind of game it is. As a shmup player, it was pretty easy for me, but enjoyable. I like how you can switch between the weapons you've picked up whenever you want. I stuck with the default gun most of the time. I found a bit weird how the laser and that other weapon make you go slower, but I can live with it.
Is the bomb not supposed to make you invulnerable? I got hit a couple of times in the middle of it. It's a bit unintuitive considering in pretty much any shmup it's pretty much a get out of jail card.
I have some peeves about the shift/slow down button. I don't like how the slow down takes some time to start after you press the button, especially considering I was using it to micro adjust my position since the normal movement is very fast. I think you could add a dedicated focused/slow movement button separate from bullet time.
The horizontal movement rate being different from the vertical movement didn't bother me, but it's a bit odd considering this is a widescreen game.
Also, I couldn't read the tutorial properly because the hud was covering the text. I think it would be nice if you could advance the tutorial at your own pace. Same with the text in the cutscenes. I had some other minor UI glitches like different option menus overlapping each other.
Some kind of gallery mode where you can view the sprites would be nice. The action is frantic so you can't pay too much attention to all the fantastic details and the girls while playing.
Were the voices AI? I liked how the shopkeeper talked better.